This invention relates to work reduction by rolling rings, such as the reduction of billets to bars and bars to bars of smaller cross-section, or to rods, or to wire. This invention has particular relationship to the prevention or suppression of the rotation of the rolling rings relative to the arbor on which they are mounted under the high tangential reactive forces exerted on the rolling rings during the reduction. To the extent that its teaching is necessary or desirable to supplement the teaching of this application, U.S. Pat. No. 4,117,705 to Martin J. Dempsey (herein Dempsey) is incorporated herein by reference.
Dempsey is typical of the prior art on reduction of the type to which this application relates. Dempsey discloses reduction apparatus with rolling rings (51, (FIG. 1) in which the mandrel or arbor 23 carrying the rolling rings is elongated and thereby tensioned by expansion of a chamber 261 whose boundaries are the shoe 71, the flanged activator 73 and the mandrel. Before the expansion, there is a peripheral gap 263 between the shoe 71 and the activator 73 which is too narrow to receive a split spacer 77. After the expansion, the gap is widened just sufficiently to receive the split spacer which is dimensioned to fill the gap. When the pressure in the chamber 261 is removed, the split ring prevents the mandrel from retracting so that the mandrel remains elongated and its restoring force is applied to prevent rotation of the rolling rings relative to the mandrel.
The apparatus disclosed in Dempsey has operated satisfactorily for many years. But difficulty has been experienced when it became necessary to replace the rolling rings. The replacement resulted in work-reducing apparatus whose dimensions are slightly different than the replaced apparatus. Such difference involves the split spacer 77 and the gap 263 whose dimensions and that of the widened gap in actual practice differ only by a few thousandths of an inch. Typically, the split spacer has a width of 0.270-inch and the gap is widened from 0.2456 to 0.272-inch. Changes in the dimensions of the apparatus on replacements have resulted in a gap which is too narrow or too wide for the spacer and have required replacement of the spacer.
It is accordingly an object of this invention to overcome the disadvantage of the prior art work-reducing apparatus and to provide apparatus which shall not require provision of a new spacer on replacement of worn out rolling rings and other parts. Another object of this invention is to provide work-reducing apparatus in which the split spacer of prior art shall be replaced by a mechanism which shall not be affected by changes in the dimensions of the apparatus on replacement of rolling rings.